Why Does My Car Smell, and What Can I Do About It?

Knowing whether the problem is dangerous, or just unpleasant, can take detective work. Follow your nose to find the source of the problem. Smells may come from inside. They may come from outside the car, including from under the hood or under the car.

Find the Reason for Your Car’s Smelly Interior

Soursmells: They say you shouldn’t cry over spilt milk, but when dairy is left to go bad, it’s enough to make anyone weep. Food containers and spoiling food leave a sour smell in your car.

Eating in the car is a way of life for many people. If you and your family are often snacking on the go, it’s nearly impossible not to have an occasional spill.

Clean out wrappers and beverage bottles. Check under seats, in storage compartments and under the mats. Vacuum, shampoo and deodorize the interior to clear out crumbs, spills and stains. For stubborn stinks, get a detailer to go over every inch of the interior.

Must and mildew odor: Musty odors happen when a car’s interior gets wet. If your car leaks or you left the window open, rain may have saturated the carpets and mats. A good cleaning and airing out should take care of the smell. If it doesn’t, you may need to replace the mats.

If you suspect a leak, check around the windows, doors, seams and the sunroof. Your car may need new weather stripping. A windshield rock chip can progress to a crack that lets water in. Get leaks repaired ASAP because here in Washington, it’s only a matter of time before the next rainfall.

If you notice the smell only when you turn on the heater or air conditioner, then you have a problem with the AC evaporator. Running the AC causes water to collect in an evaporator box. If the drain from the box is clogged, moisture could seep into the car, most likely on the passenger side.

If there isn’t a leak, your car’s evaporator may be growing mildew. To clean out the system, get your air conditioner serviced. Be sure to mention the musty odor.

Burning scent: A short in the electrical system or trouble with an electrical component can cause a burning odor inside your car. Electrical systems are complex in a modern car. Make an appointment with your mechanic for a diagnosis.

Sweet smell: When you smell something sweet inside the car, it means the heater core is leaking coolant. Coolant smells sweet. The heater core lives in the dashboard. It can leak into the cabin. Learn more by reading our blog post about busted heater cores.

Diagnose Odors Coming From a Car’s Exterior

Unusual smells from the exterior of the car may indicate a mechanical problem. Leaks are a common culprit. So are worn parts.

Here are some common smells and their causes.

Sweet smell: Coolant smells the same whether it’s leaking inside or outside the car. You’ll smell something sweet if coolant drips on a hot engine. You may also see fluid on the ground beneath the car. Coolant is toxic. Keep kids and pets away from it.

Leaks can come from the radiator, a hose, a cylinder head or a manifold gasket. Get the radiator, radiator cap and radiator hoses checked.

Burning odor #1 – Hot oil: This smell, often accompanied by smoke, means oil is leaking onto a hot engine or exhaust manifold. Oil can drip in different areas of a car. You or your mechanic will need to look under the hood. You may also see oil stains on the pavement or garage floor.

Burning odor #2 – Hot carpet: A burning carpet smell means the brake pads are getting too hot. Brakes in good condition shouldn’t overheat from ordinary town and city driving. If your brakes are overheating under normal conditions, it could mean part of the brake system is dragging or has seized. Have the brakes serviced right away.

Burning odor #3 – Burning paper: If the clutch is slipping it will burn off the facing. You’ll smell this when you’re driving. The clutch facing is similar to paper. If the clutch is slipping, you’ll smell something like singed newspapers.

Gas: Cars manufactured after about 1980 should never have an odor of gas. When they do, it means there’s a fuel leak. The problem may be in a fuel-injector, the tank or in a vent hose. If there’s a leak, you’ll notice this smell when the car is parked. The smell is stronger when a car is in a garage and when the weather is warm.

Rotten eggs or sulfur: If you smell this putrid odor while the engine is running, it’s a sign the catalytic converter has failed. You’ll need to get a new one installed.

Get Rid of Odor At Our Battle Ground Car Wash

There’s another bad smell that can come from the car’s exterior. This one doesn’t have a mechanical source. If you’ve driven over something smelly, your car’s underside may require a good washing and undercarriage spray.

It’s not easy to wash beneath a car when you’re working at home. Come visit the Clean Machine Car Wash. We’ll get every surface of your vehicle clean and smelling nice.